vdrop9
Acquire/release a hold on a vnode
Part of vhold(9).
Usage
#include <sys/param.h>
#include <sys/vnode.h>
void
vhold(struct vnode *vp);
void
vdrop(struct vnode *vp);
Overview
The vhold() function increments the v_holdcnt of the given vnode. If the vnode has already been added to the free list and is still referenced, it will be removed.
The vdrop() function decrements the v_holdcnt of the vnode. If the holdcount is less than or equal to zero prior to calling vdrop(), the system will panic. If the vnode is no longer referenced, it will be freed.